Investigation of black phosphorus field-effect transistors and its stability

摘要

In this paper, the electrical properties of black phosphorus(BP) are investigated. Back-gated field-effect transistors (FETs) array with different channel length are fabricated on the same BP nanoflake. The device exhibits high current on/off ratio (5 × 10~3), high field-effect mobility (130 cm~2 V~(-1) s~(-1)) and low contact resistance (917 Ω μm). In addition, the stability of BP device is also explored. Results show that the 10 nm Al_2O_3 dielectric layer can effectively depress the exposure of BP flakes with air and then protect the BP devices from ambient degradation. There is no noticeable degradation in device performance for the devices with 10 nm Al_2O_3 passivating layer even after being exposed in air for 2 weeks.